#include <iostream>

using namespace std;

class person {
	public:
		static int age;
};

int person::age = 18;

void test1() {
	person p1;
	cout << "p1:" << p1.age << endl;

	person p2;
	p2.age = 20;
	cout << "p1:" << p1.age << endl;

//	cout << "p:" << person.age << endl;
	cout << "p:" << person::age << endl;
}

int main() {
	test1();

	return 0;
}